Osborne J E, Hutchinson P E
Department of Dermatology, Leicester Royal Infirmary, Leicester, LE1 5WW U.K.
Br J Dermatol. 2001 Mar;144(3):476-83. doi: 10.1046/j.1365-2133.2001.04071.x.
Breslow thickness is a major predictor of prognosis in cutaneous malignant melanoma (MM) and patients continue to present with thick lesions, which have a poorer prognosis.
To investigate correlations of Breslow thickness with demographic variables, tumour site, clinical features, false negative diagnostic rate and clinic of primary referral.
Data were obtained from the records of 738 patients with histologically diagnosed cutaneous MM. Tumours included were in situ and invasive MM and lentigo maligna melanoma. In view of the skewed distribution of MM thickness, categories of MM thickness were used for analysis, using the commonly applied cut-offs of 0.75, 1.5 and 3.5 mm. The variables investigated were particularly associated with changes in the proportion of the thickest group, 'thick' MMs. The proportion of this thickness category is proposed as an appropriate and sensitive variable for the investigation of correlations with MM thickness. Thickness >/= 1.5 mm has also been considered in view of its prognostic significance.
Results were similar for the two thickness groups, but more significant for the thick group. The previously described correlations of tumour thickness and increasing age (P < 0.00001) and location on head and neck (P = 0.0002), together with the independence of these variables, have been confirmed. The correlation with male gender was also confirmed but this was weak (P = 0.05). Novel findings were correlations of Breslow thickness with all features of the seven-point checklist (P varying from P = 0.01 to P < 0.00001) and tumour elevation (P < 0.00001). In general in the seven-point checklist, the absence of the major features (except variation in size) (P < 0.00001) and presence of minor features (except altered sensation) (P varying from P = 0.004 to P < 0.00001) were strongly associated with thick MMs. These results for tumour thickness are a further argument for retention of the minor features of the seven-point checklist. False negative diagnosis was found to be correlated with tumour thickness (P < 0.02) but this relationship was lost on multivariate analysis with inclusion of the clinical features. MM thickness was highly correlated with primary referral clinic (P < 0.00001). Only approximately 8% of MMs presenting to the Pigmented Lesion Clinic (PLC) were thick, while the proportion presenting to general dermatology was about three times greater and to plastic surgery about five times greater. This was maintained on multivariate analysis, including all other variables and, therefore, there must be other determining factors of referral not examined in the study. Conclusion MM thickness is associated with increasing age, male gender, location on the head and neck, all features of the seven-point checklist, tumour elevation and referral to the PLC. It is important to investigate further the reasons for general practitioner referral of different thickness MM to different types of clinic, as referral to clinics other than the PLC results in delay in the first hospital appointment, and it is now apparent that thicker lesions are disproportionately affected.
Breslow厚度是皮肤恶性黑色素瘤（MM）预后的主要预测指标，仍有患者出现厚度较大的病灶，其预后较差。
研究Breslow厚度与人口统计学变量、肿瘤部位、临床特征、假阴性诊断率及初次转诊科室之间的相关性。
从738例经组织学诊断为皮肤MM的患者记录中获取数据。纳入的肿瘤包括原位和浸润性MM以及恶性雀斑样痣黑色素瘤。鉴于MM厚度的分布呈偏态，采用MM厚度类别进行分析，使用常用的0.75、1.5和3.5mm截断值。所研究的变量特别与最厚组（“厚”MM）比例的变化相关。该厚度类别的比例被认为是用于研究与MM厚度相关性的合适且敏感的变量。鉴于其预后意义，也考虑了厚度≥1.5mm的情况。
两个厚度组的结果相似，但厚组的结果更显著。先前描述的肿瘤厚度与年龄增长（P<0.00001）以及头颈部位置（P = 0.0002）的相关性，以及这些变量的独立性得到了证实。与男性的相关性也得到了证实，但较弱（P = 0.05）。新发现是Breslow厚度与七点检查表的所有特征（P值从P = 0.01到P<0.00001）以及肿瘤隆起（P<0.00001）相关。总体而言，在七点检查表中，主要特征（除大小变化外）的缺失（P<0.00001）和次要特征（除感觉改变外）的存在（P值从P = 0.004到P<0.00001）与厚MM密切相关。这些肿瘤厚度的结果进一步支持保留七点检查表的次要特征。发现假阴性诊断与肿瘤厚度相关（P<0.02），但在纳入临床特征进行多变量分析时这种关系消失了。MM厚度与初次转诊科室高度相关（P<0.00001）。就诊于色素沉着病变诊所（PLC）的MM中只有约8%是厚的，而就诊于普通皮肤科的比例约为其三倍，就诊于整形外科的比例约为其五倍。在包括所有其他变量的多变量分析中这一情况得以维持，因此，研究中未考察的转诊必定存在其他决定因素。结论MM厚度与年龄增长、男性、头颈部位置、七点检查表的所有特征、肿瘤隆起以及转诊至PLC相关。进一步研究全科医生将不同厚度的MM转诊至不同类型科室的原因很重要，因为转诊至PLC以外的科室会导致首次医院预约延迟，现在很明显较厚的病灶受到的影响不成比例。
